Welcome to the sixth annual Every Play Counts All-Defensive Teams, a tradition that started in 2005-06 at 82games.com and has become a fixture here at Basketball Prospectus since its inception.

Before getting to the teams, a big-picture thought. An important finding of statistical analysts that confirms conventional wisdom is that big men are far more important defensively than perimeter players. We observe this both via box-score statistics and plus-minus numbers. If WARP is split into offensive and defensive components, 20 of the top 25 players in the NBA this season are power forwards or centers. Meanwhile, an offensive/defensive split of adjusted plus-minus tends to show offensive value decreasing and defensive value increasing down the position spectrum from point guard to center. The way the game is played, post players simply have more defensive responsibility and are more involved in the game at that end of the floor.

This is important for a couple of reasons. It explains why the Defensive Player of the Year should almost always be a big man as well as why my entire ballot was made up of posts. Additionally, it's because defensive assignments and value are so different between point guards and shooting guards and small forwards and power forwards that I like to pick my All-Defensive Team strictly in terms of positions. When the NBA's head coaches cast their All-Defensive votes, by contrast, they are merely asked to pick two guards, two forwards and a center. For the most part, I aim to keep players where they defend the majority of their minutes, though that is not always clear.

The selection process starts, naturally, with all the game action I've watched this season in person and on television (much more of the latter than the former, alas). Quantifying defense remains a challenge for statistical analysts. Still, there are many tools we can use to bluntly evaluate individual defense. Specifically, I put together a spreadsheet with the following information about each player:

Statistics about individual defense from Synergy Sports, depending on the position: defense against pick-and-roll ballhandlers for point guards, isolation plays for wings and post-up defense for big men.

POINT GUARD

First Team - Kyle Lowry, Houston
A long-time recipient of honorable mention accolades, Lowry took a leap forward this year by playing his best defensive basketball as a starter. Lowry's strength and low center of gravity allow him to play much bigger than his height (just 6'0"). Meanwhile, Lowry is also quick for the position and racks up steals. The Rockets struggled defensively this season, but they were far better with Lowry on the floor, allowing 6.3 fewer points per 100 possessions.

Second Team - Rajon Rondo, Boston
Rondo's individual numbers were as strong as ever. He ranked second among point guards in steal rate (trailing Chris Paul) and continues to do an excellent job defending the pick-and-roll. Lowry simply beat Rondo out for the top spot, and Rondo's poor net defensive plus-minus (the Celtics were 2.1 points worse defensively with him on the floor) gave me some pause.

Honorable Mention

Chris Paul, New Orleans: Basically a 2A, Paul could easily have merited a spot on one of the two teams. The most underrated aspect of his defense is how terrific Paul is on the glass for his size; among players who defended the point, only John Wall had a higher defensive rebound percentage.

Toney Douglas, New York: During his second season, Douglas came into his own defensively, hounding opponents with his quick hands. Only Lowry had a superior net defensive plus-minus. The biggest factor holding Douglas back was his reserve role, which meant he played fewer minutes than the players ranked ahead of him.

Mario Chalmers, Miami: Honestly, Chalmers isn't in the same league as the other four honorees at the point, but someone had to earn the last honorable mention. Chalmers is a solid ballhawk who more than holds his own physically.

SHOOTING GUARD

First Team - Tony Allen, Memphis
The reason Allen merits defensive recognition this season is his improved offense. That sounds silly at first glance, but Allen's unexpected development into a reliable scoring option allowed the Grizzlies to start him over the second half of the season, giving him the kind of minutes necessary to make my All-Defensive Team. Allen's defensive prowess was no secret in Boston; he's defended Kobe Bryant as well as anyone in the league, for example. However, Allen used to give back that production with silly turnovers and misses around the rim. What makes Allen unique defensively is that he's a stopper who also racks up steals. In fact, he led the NBA in steal percentage for the second consecutive season, and nobody else was particularly close.

Second Team - Manu Ginobili, San Antonio
Ginobili is one of the league's most underrated wing defenders. Since Bruce Bowen's decline and retirement, he's served as the Spurs' stopper while also playing the passing lanes for steals. Ginobili has size, quickness and terrific instincts. He was especially effective this season in isolation situations, allowing just 0.73 points per play.

Honorable Mention

Thabo Sefolosha, Oklahoma City: The buzz around Sefolosha as the next Bruce Bowen died down quickly this season. In part, Sefolosha has been buried by the emergence of James Harden, but we may look back on the way he defended the first four months of the 2009-10 season as out of line with the rest of his career. Sefolosha's individual numbers were still solid--he rebounds well for a stopper--but the Thunder defended better with him on the bench.

Kobe Bryant, L.A. Lakers: As he ages, Bryant has to coast a bit more at the defensive end of the floor, but there are few tougher matchups in the league than a focused Bryant. He was a hair behind Ginobili in terms of stopping isolations, allowing 0.74 points per play.

Dwyane Wade, Miami: Wade was surprisingly poor against isolations (0.89 points per play) and the Heat was better defensively when he was on the bench, but I'm inclined to write both off as fluky numbers. Wade remains as effective as a help defender in the paint as any perimeter player, blocking shots against much bigger opponents.

SMALL FORWARD

First Team - Andre Iguodala, Philadelphia
Iguodala has never gotten enough attention for his defense, but this is his debut on my All-Defensive First Team. A couple of things came together here. First, Iguodala's experience at the FIBA World Championship helped demonstrate the impact he could make at the defensive end. That was backed up by the best defensive coach he's had during his career, Doug Collins. The combination helped Iguodala emerge as the anchor of one of the league's most improved defenses.

Second Team - LeBron James, Miami
In plus-minus terms, the Heat relied more on Wade for offense and James for defense. Miami allowed 5.4 more points per 100 possessions when James hit the bench. His size helped mask the weaknesses of the Heat's frontcourt, especially on the defensive glass. When he locks in defensively, James can swallow up perimeter players in a way essentially unmatched throughout the league.

Honorable Mention

Luol Deng, Chicago: I recently stunned a guy who knows things about the NBA with the fact that Deng had played more minutes than Derrick Rose. That shows how invaluable Deng was to Tom Thibodeau at both ends of the floor. His length and quickness make him the best individual defender for his position on the league's best defense (and, amazingly, the only one singled out here).

Paul Pierce, Boston: While his net plus-minus partially reflects the Celtics' difficulty finding a backup for him, all of Pierce's numbers are strong. He allowed just 0.74 points per isolation, second among the players I considered to the Lakers' Ron Artest (an incredible 0.58 ppp, though the rest of his stats were not as good).

Shane Battier, Memphis: Though not the dominant wing defender he once was, Battier is still in the league's upper echelon thanks to his intelligent play, use of scouting reports and positioning. He helped the Grizzlies' defense clamp down after the trade deadline.

POWER FORWARD

First Team - Kevin Garnett, Boston
Even as he approaches age 35, Garnett remains the league's best do-everything defender. He controls the defensive glass, racks up steals and can defend the paint just as easily as he can step out against smaller players. Garnett's Synergy numbers are downright mind-boggling. Not only did he allow just 0.7 points per post up, Garnett was far and away the league's best defender against the pick-and-roll. The roll man made eight shots in 41 attempts (19.5 percent) against Garnett's defense this season. No wonder Boston competed with Chicago for the NBA's top spot in Defensive Rating all year long.

Second Team - Tim Duncan, San Antonio
I picked Duncan for the All-NBA Second Team as a center, but he's played just enough minutes at power forward to qualify for his fifth appearance on one of my All-Defensive Teams in six years--the most of ay player. The numbers confirm that Duncan has slipped badly in terms of defending the pick-and-roll, once his forte, but the rest of his defensive game remains strong. The Spurs, otherwise a weak defensive team, improved dramatically the moment Duncan stepped on the floor, allowing 6.8 fewer points per 100 possessions. Duncan also ranked fifth in the league in defensive WARP.

Honorable Mention

Josh Smith, Atlanta : Because of Smith's spacey offense, people are reluctant to embrace the value of his defensive contributions. No matter how you slice the numbers, Smith deserves to be considered among the best defenders at power forward. The Hawks allow 6.2 fewer points per 100 possessions with him on the floor. Smith was third in the league in Defensive WARP on the strength of his excellent block rate and solid steal rate. Like teammate Al Horford, Smith excels at switching out and defending guards on the perimeter.

Darrell Arthur, Memphis: Like Douglas, Arthur is a future All-Defensive Team pick when he earns a larger role. He was terrific defensively for the Grizzlies off the bench this season. They allowed 5.7 fewer points per 100 possessions when Arthur checked in the game. He's got the quickness to match all kinds of fours and held his own in the post while also blocking shots regularly. Arthur's only defensive shortcoming is that he is poor on the glass.

Serge Ibaka, Oklahoma City: Comparing Ibaka to other power forwards as a shot blocker is borderline unfair. He blocked 6.2 percent of opposing two-point attempts, a mark surpassed only by JaVale McGee. Just one other power forward (Charlotte's Tyrus Thomas) had a block rate better than 4.5 percent. Ibaka's weakness remains defending the post. He allowed .93 points per post-up opportunity, second worst among the big men I considered.

CENTER

First Team and Defensive Player of the Year - Dwight Howard, Orlando
At this point, the notion of any other player winning Defensive Player of the Year while Howard is in his prime seems almost laughable. Howard no longer blocks shots at an exceptional rate (his 4.9 percent block rate ranked 12th in the league), but the tradeoff is that he's improved his foul rate and can stay on the floor for almost 38 minutes a night. The strength of Howard's game is his glass cleaning; he's almost single-handedly responsible for Orlando leading the league in defensive rebound percentage. Overall, Howard is the biggest reason a Magic team that did not put any other players in consideration for my All-Defensive Teams ranked third in the league in Defensive Rating.

Second Team - Andrew Bogut, Milwaukee
Bogut's nasty elbow injury limited his offense all season long, but it had no such impact on his defense. Bogut ranked eighth in the league in block percentage, trailing just three players who saw starters' minutes. Quietly, the Bucks were a top-tier defensive team in the midst of a disappointing season, ranking fourth in the league in Defensive Rating. Bogut made that happen both with his help defense in the paint and his rebounding. Bogut is also handy for a 7-footer when it comes to stepping away from the basket.

Honorable Mention

Tyson Chandler, Dallas: We usually think of defense as more consistent than offense from year to year. Chandler is the exception. He's oscillated between excellent and average on defense with little explanation. Motivated after being traded to the Mavericks, Chandler's length helped Dallas improve and was useful when the team frequently went to zone defenses.

Andrew Bynum, L.A. Lakers: Over the last two months, Bynum has been as good defensively as any player in the league. Years ago, the late Al McGuire used to call Ralph Sampson an "aircraft carrier" because of his size. I think of that nickname with Bynum, who is physically imposing even compared ot other NBA centers. He simply takes up so much space it's hard for opponents to find openings in the middle.

Chuck Hayes, Houston: Arguably the league's best post defender--and inarguably the best among players who stand 6'6"--Hayes allowed just 0.73 points per post-up opportunity. More than just a specialist, Hayes also moves his feet well enough to defend the perimeter, draws charges and comes up with more steals than most five men, compensating for his inability to block shots.